The Petrochemical Features of the Volcanic Rocks in Okinawa Trough and Their Geological Significance
《变质作用与大陆动力学学术讨论会》在北京召开

It has been found that volcanic rork in Okinawa Trough includes basalt, basaltic andesite, andesite, trachyandesite, trachydacite, dacite and rhyolite. The studies show that the rocks in Okinawa Trough is of a subalkaline rock series.The basic rocks belong to a transitional form between tholeiite series and calc alkalic series while most of the intermidiate rocks and acid rocks belong to calc alkalic series.They were formed since Policene and at different stages during the fractional crystallization of the initial basaltic magma which originated from the enriched mantle under the bottom.The consistency in the fractional crystallzation devoloping and the variance in the relationships among petrochemical indexes were resulted from the independent evolving stocks of the magma separated by the rift block, which was originally quick rising and non hybridized.